Ignition means for fluid fuel burners



June 13, 1944. ,1 C, ENGLISH 2,351,325

IGNITION MEANS FOR FLUID FUEL BURNERS Filed nec. 2e, 1940 JNVENTOR. JO/7Al C W62 /S/i Patented June 13, 1944 IGNITION MEANS FOR FLUID FUEL BURNERS John C. English, Cedar Rapids, Iowa, assignor to Johnson Gas Appliance lds, Iowa,

Company, Cedar Rapa corporation of Delaware Application December 26, 1940, Serial No. 371,708

3 Claims.

This invention relates to iiuid fuel burners and has particular relation to electrical ignition devices for such burners.

Fluid fuel burners, and particularly those built for the use of gas, when provided with means for electrically igniting the gas, normally employ a high voltage transformer and a spark gap.

This method of providing an ignition spark has been found to be more or less satisfactory except as regards cost, which may be relatively high if a reliable transformer is employed.

It is, therefore, a primary object of my invention to provide a simplified electrical ignition device for iiuid fuel burners and one which is relatively inexpensive to manufacture and substantially trouble free.

A further object of my invention is to provide electrical ignition means for gas burners and the like from which the transformer, normally employed, is entirely eliminated.

A still further object of my invention is to provide electric ignition means suitablel for use in connection with either alternating or direct current power supply systems.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawing and following specification, wherein is dicclosed a single exemplary embodiment of the invention, with the understanding, however, that such changes may be made'therein as fall within the scope of the appended claims, without departing from the spirit of the invention.

In said drawing:

Figure 1 is a drawing partly in top elevation and partly in section illustrating the structure of a fuel supply and control system as it may be applied to a cook stove or oven and with a pilot burner embodying an electrical ignition device ,constructed in accordance with my invention.

Figure 2 is a view in perspective of the pilot burner and ignition device illustrated in Figure 1,' and Figure 3 is a fragmentary view in section of the armature and its mounting means.

Referring now to the drawing:

The fuel supply system including a safety valve and pilot-burner-actuated throttling valve, shown in Figure 1 in connection with my improved electrical ignition device, is disclosed in detail in my co-pending application Serial Number 327,399 filed April 2, 1940, Patent No. 2,305,243, and will therefore be described but briefly in this speciiication.

The supply of gas to the system is turned on at a service valve II, from which gas is supplied through a thermostatic oven-temperature regulator I2 to a main control valve I 3'. This valve controls the ow of fuel to the main oven burner I 4. Immediately the service valve II is opened, however, gas is supplied through a conduit I6 to a chamber I'I in the main valve adjacent the valve actuating diaphragm I8 and, at the same time, to the pilot burner I9 through a throttling valve 2|. 'I'he outlet side of the throttling valve 2| is also connected to a chamber adjacent the opposite side of the valve actuating diaphragm I8.

The throttling valve is normally open when the pilot burner and main burner are not ignited and the gas may pass freely through the throttling valve to both sides of the valve actuating diaphragm I8 as well as to the pilot burner. After the pilot burner is ignited, as will be hereinafter described, the heat of the pilot flame actuates the thermal element 22 to partiallly close the throttling valve 2I. The resulting drop in pressure on one side of the diaphragm I8 permits the main valve I3 to open to supply gas to the main burner.

Ignition of the pilot burner is controlled by a diaphragm actuatedswitch 26. This switch is closed by any differential of pressure between the supply conduit 2l and the outlet side of the main valve.

It is apparent that the ignition device will be energized immediately when the gas is turned on at the service valve. This electric ignition is maintained until after the main valve has opened and gas has entered the main burner supply conduit.

The ignition device is preferably constructed as an integral part of the pilot burner casting 28 and of a material such as malleable or cast iron having a relatively low magnetic reluctance. An enlarged boss 29 comprising a part of the pilot burner casting is provided with a. cylindrical recess or well 3| for receiving an electromagnet 32. 'I'his magnet is wound of insulated wire upon a soft iron core 33 which is secured within and to the bottom of the recess 3| by a screw 34. The terminal leads of the electromagnet are brought out through holes 36 at the rear-of the boss and .connected in series with an alternating yor direct current power supply line, with thedgnition switch 23 and with a pair of breaker contacts 43 and 43a.

A small armature -3`l of soft iron is formed as shown in Figure 3 and provided with a clamp 45 to grip a tubular insulating sleeve 38 to permit the armature to be mounted forfrce swinging movement on a pivot pin adjacent the end of the magnet core. This pivot pin may be in the form of a slender screw 38 mounted transversely of the magnet recess 3|. The boss is preferably provided with a pair of spaced ears 4| adjacent the open end of the magnet recess and the ears are provided with openings for receiving the screw or pivot pin. An insulating disk, such as shown at 43, or other suitable means should be employed to prevent contact between the armature and the core of the magnet.

A vibrator arm 42 is secured to the armature so that any movement of the amature will be transmitted to the arm and cause a movement greatly increased in amplitude at the free end thereof. This free end of the vibrator arm and the outer end of the pilot burner casting are provided with a pair of contacts 43 and 43a respectively, previously mentioned, of platinum, silver, or any other suitable material. A flexible conductor 44 attached to the arm near its mounting point connects the vibrator contacts 43 and 43a, the main ignition switch 26, the power line, the electromagnet, and a fixed resistance member 46 in series. One side of the power line is normally grounded, as shown at 41, and the vpilot burner itself is also grounded as at 48.

The contacts 43 and 43a are, of course, normally closed except when the ignition device is functioning, and when the pilot burner and ignition mechanism are mounted horizontally as shown, the weight of the vibrator arm is suillcient to return the contact 43 to closed position against the contact 43a. The movable member comprising the armature and vibrator arm may, however, be provided with a weighted arm 49 (Figures 2 and 3) to return the contacts 43 -to closed position if the pilot burner is to be mounted vertically with the contacts uppermost. The Weight of and the position of the weighted arm 49 rela.- tive to the other parts of the movable member obviouslywill vary and will depend upon the position in which the pilot burner and ignition device is to be mounted.

It may now be understood that, when gas is admitted to the main valve, the ignition switch 26 will be closed to energize the electromagnet 32 to attract the armature and thus break the current passing through the contacts 43 and 43a. 'I'his will result in a rapid vibration of the contact 43 and creation of a more or less continuous spark between it and the contact 43a.

The pilot burner is provided with one or more ports so placed as to direct ajet of gas across or closely adjacent the contacts 43 and 43a. The main pilot jets are of course arranged to be ignited by the ame from the ports 5I.

The fixed resistance 48 is not essential to the operation of the device, but I have found it advisable to employ such a resistance in order lto permit the electromagnet to be wound for a lower-than-line voltage, and thus not only permit a reduction in size of the magnet winding,

' for igniting the fuel.

but also permit the same size electromagnet to be used on supply lines having voltages other than the usual volts simply by the addition of the proper size resistance.

Although I have described a specific embodiment of my invention, it is apparent that modications thereof may be made by those skilled in the art. Buch modications may be made without departing from the spirit and scope of my invention as set forth in the appended claims.

I claim as my invention:

l. In a fluid fuel burner. means for initiating ignition including a pair of contacts, an electromagnet and a source of electric current in series. a support havingv a bore receiving said electroymagnet, one of the contacts being mounted on a movable member, the movable member having an amature portion so positioned in said bore as to be attracted by the electromagnet, a pivot across saidbore for said movable member, an insulating sleeve between said pivot and said movable member, the attraction of the magnet for said armature portion causing the member to move and break the contact thusA breaking the electric circuit and de-energizing the magnet permitting the movable member to return to its original position remaking the contact. the alternate making and breaking of the contact causing electric arcs across the gap between the contacts, and means for directing a stream of fuel into or near the gap to cause ignition thereof.

2. In an ignition means for fluid fuel burners. a fixed contact and amovable contact positioned adjacent the burner to ignite fuel issuing therefrom, means for providing an electric current between the contacts, and means including an electromagnet and an armature for moving the movable contact to produce an arc between the fixed and movable contacts, a support for said electromagnet, a. pivot carried thereby for said armature, an insulating sleeve surrounding said pivot and a clamp for securing said armature to said sleeve, said sleeve being longer than the Vwidth of said clamp and said clamp being positioned spaced from the ends of the sleeve to prevent electricaly contact between the ends of the clamp and said support.

3. In an ignition means for auid fuel burner, a fixed contact mounted on the burner, supporting means adjacent the burner and having a bore, a pivoted member, a pivot therefor across said bore and adjacent one side thereof, an electro-magnet mounted in said bore, said pivoted member having a contact on one end thereof and the other end thereof being magnetic and being positioned in said bore and in the eld of force of said electro-magnet, and electrical connections whereby the passage of electric current through the electro-magnet is controlled by the contacts, whereby movement of the contact on the pivoted member produces an arc between the contacts JOHN C. ENGLISH. 

